Topic overview

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Essential linoleic and α-linolenic acids must come from the diet because humans lack the desaturases needed to produce them. Linoleic acid gives rise to arachidonic acid, a precursor of eicosanoids, while omega-3 fatty acids such as EPA and DHA have distinct metabolic effects. The topic also covers thermogenesis in brown adipose tissue, appetite and insulin-sensitivity signals from adipocytes, and protection against lipid peroxidation. Cholesterol handling is illustrated by LCAT, CETP, and ABCA1, whose dysfunctions are linked to characteristic disorders. Further sections address hormone-sensitive lipase, ketone bodies, fatty-acid oxidation in mitochondria and peroxisomes, sphingolipid degradation, and fat malabsorption with fat-soluble vitamin deficiency.